Preparation

Bring a large saucepan of
water to a boil. Reduce heat
to medium-low; season lightly
with salt. When water is at
a gentle simmer, add shrimp.
Poach until just opaque in the
center, 2-4 minutes. Drain;
transfer shrimp to a medium
bowl of ice water to cool. Drain;
wipe out bowl.

Whisk mayonnaise, celery,
chives, oil, lemon juice, and
horseradish in a medium bowl to
blend; season to taste with salt
and pepper. Chop shrimp into
small pieces (about 1/3"); add to
bowl with mayonnaise mixture.
Stir to coat. DO AHEAD: Shrimp
salad can be made 1 day ahead.
Cover and chill.

Preheat oven to 375°F. Using
a small serrated knife, make a
1/2"-deep cut across the top of
each dinner roll and gently pry
open roll with your fingers to
create a mini New England-style
hot dog bun. Lightly brush inside
of rolls with butter; place on a
rimmed baking sheet. Toast until
light golden, about 8 minutes.
Let cool slightly.